WASHINGTON, March 23 (Reuters) – Banks, exchanges and traders have only days left to convince regulators to take a lighter touch on tough curbs on commodity market speculation, after a four-year fight against proposals to limit their role in the markets.

Having almost certainly lost the battle to forestall position limits in some form, traders see victory or defeat depending on the details of the proposed regulations.

With billions of dollars at stake, opponents are still hoping to gain ground on issues including separate “class limits” for futures and swaps, a heavy compliance burden, and whether wheat and corn markets need special protections.

After months of behind-the-scenes lobbying, the industry’s biggest players will publicly show their hand in the final hours before the March 28 deadline for feedback on the Commodity Futures Trading Commission’s proposal, which was released for 60 days of public comment in January.

Their arguments are well-rehearsed: the plan will make it harder for companies to hedge risk, more costly for consumers to protect themselves from higher prices and, ultimately, markets more volatile by driving away liquidity.

And they come at a time when soaring oil prices has revived debate about the role of speculators in driving up costs.